Heterocyclic quinolizine derived M1 receptor positive allosteric modulators

ABSTRACT

The present invention is directed to novel 3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizine derived compounds of generic formula (I) or a pharmaceutically acceptable salt thereof, which are M1 receptor positive allosteric modulators and that are useful in the treatment of diseases in which the M1 receptor is involved, such as Alzheimer&#39;s disease, schizophrenia, pain or sleep disorders. The invention is also directed to pharmaceutical compositions comprising the compounds, and to the use of the compounds and compositions in the treatment of diseases mediated by the M1 receptor.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the National Stage of International Application No.PCT/US2011/033721 filed on Apr. 25, 2011, which claims the benefit under35 U.S.C. 119(e) of U.S. Provisional Application No. 61/329,690, filedApr. 30, 2010.

FIELD OF THE INVENTION

The invention is directed to a class of heterocyclic quinolizine derivedcompounds, their salts, pharmaceutical compositions comprising them andtheir use in therapy of the human body. In particular, the invention isdirected to a class of 3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizinederived compounds which are muscarinic M1 receptor positive allostericmodulators, and hence are useful in the treatment of Alzheimer's Diseaseand other diseases mediated by the muscarinic M1 receptor.

BACKGROUND OF THE INVENTION

Alzheimer's Disease is a common neurodegenerative disease affecting theelderly, resulting in progressive memory impairment, loss of languageand visuospatial skills, and behavior deficits. Characteristics of thedisease include degeneration of cholinergic neurons in the cerebralcortex, hippocampus, basal forebrain, and other regions of the brain,neurofibrillary tangles, and accumulation of the amyloid β peptide (Aβ).Aβ is a 39-43 amino acid produced in the brain by processing of thebeta-amyloid precursor protein (APP) by the beta-amyloid proteincleaving enzyme (“beta secretase” or “BACE”) and gamma-secretase. Theprocessing leads to accumulation of Aβ in the brain.

Cholinergic neurotransmission involves the binding of acetylcholineeither to the nicotinic acetylcholine receptor (nAChR) or to themuscarinic acetylcholine receptor (mAChR). It has been hypothesized thatcholinergic hypofunction contributes to the cognitive deficits ofpatients suffering from Alzheimer's Disease, Consequently, acetylcholinesterase inhibitors, which inhibit acetylcholine hydrolysis, havebeen approved in the United States for use in the treatment of thecognitive impairments of Alzheimer's Disease patients. While acetylcholinesterase inhibitors have provided some cognitive enhancement inAlzheimer's Disease patients, the therapy has not been shown to changethe underlying disease pathology.

A second potential pharmacotherapeutic target to counteract cholinergichypofunction is the activation of muscarinic receptors. Muscarinicreceptors are prevalent throughout the body. Five distinct muscarinicreceptors (M1-M5) have been identified in mammals. In the centralnervous system, muscarinic receptors are involved in cognitive,behavior, sensory, motor and autonomic functions. The muscarinic M1receptor, which is prevalent in the cerebral cortex, hippocampus andstriatum, has been found to have a major role in cognitive processingand is believed to have a role in the pathophysiology of Alzheimer'sDisease. See Eglen et al, TRENDS in Pharmacological Sciences, 2001,22:8, 409-414.

In addition, unlike acetyl cholinesterase inhibitors, which are known toprovide only symptomatic treatment, M1 agonists also have the potentialto treat the underlying disease mechanism of Alzheimer's Disease. Thecholinergic hypothesis of Alzheimer's Disease is linked to bothβ-amyloid and hyperphosphorylated tau protein. Formation of β-amyloidmay impair the coupling of the muscarinic receptor with G-proteins.Stimulation of the M1 muscarinic receptor has been shown to increaseformation of the neuroprotective αAPPs fragment, thereby preventing theformation of the Aβ peptide. Thus, M1 agonists may alter APP processingand enhance αAPPs secretion. See Fisher, Jpn J Pharmacal, 2000,84:101-112.

However, M1 ligands which have been developed and studied forAlzheimer's Disease have produced side effects common to othermuscarinic receptor ligands, such as sweating, nausea and diarrhea. SeeSpalding et al, Mol Pharmacol, 2002, 61:6, 1297-1302.

The muscarinic receptors are known to contain one or more allostericsites, which may alter the affinity with which muscarinic ligands bindto the primary binding or orthosteric sites. See, e.g., S. Lazareno etal, Mol Pharmacol, 2002, 62:6, 1491-1505; S. Lazareno et al, MolPharmacol, 2000, 58, 194-207. See also WO2005056552, WO2005030188 andWO2007067489.

Thus the compounds of the invention, which are muscarinic M1 receptorpositive allosteric modulators, are believed to be useful in thetreatment of Alzheimer's Disease and other diseases mediated by themuscarinic M1 receptor.

SUMMARY OF THE INVENTION

The present invention is directed to novel3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizine derived compounds of genericformula (I) indicated below or a pharmaceutically acceptable saltthereof, which is useful as an M1 receptor positive allostericmodulator.

The invention is further directed to methods of treating a patient(preferably a human) for diseases or disorders in which the M1 receptoris involved, such as Alzheimer's disease, cognitive impairment,schizophrenia, pain disorders and sleep disorders, by administering tothe patient a therapeutically effective amount of a compound of generalformula (I), or a pharmaceutically acceptable salt thereof The inventionis also directed to pharmaceutical compositions which include aneffective amount of a compound of formula (I), or a pharmaceuticallyacceptable salt thereof, and a pharmaceutically acceptable carrier, andthe use of the compounds and pharmaceutical compositions of theinvention in the treatment of such diseases.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment, the invention is directed to heterocyclic quinolizinecompounds of general formula (I)

and pharmaceutically acceptable salts thereof; wherein

-   R¹ represents —NR²R³, or a nitrogen containing C₅₋₁₀ heterocyclyl;    wherein said heterocyclyl is optionally substituted with one or more    of R^(a);-   R² and R³ independently represent    -   (a) hydroxy,    -   (b) —O—C₁₋₆ alkyl, said alkyl optionally substituted with 1 to 3        groups of R^(a);    -   (c) —C₁₋₆ alkyl, said alkyl optionally substituted with 1 to 3        groups of R^(a);    -   (d) -hydrogen;

R^(a) represents:

-   -   (a) halogen,    -   (b) hydroxy,    -   (c) —O—C₁₋₆ alkyl, said alkyl optionally substituted with 1 to 3        groups of halo;    -   (d) —C₁₋₆ alkyl, said alkyl optionally substituted with 1 to 3        groups of halo;    -   (e) cyano,    -   (f) —NR^(A)R^(B), wherein R^(A) and R^(B) are selected from the        group consisting of        -   (i) hydrogen,        -   (ii) —C₁₋₆ alkyl,        -   or R^(A) and R^(B) are linked together with the nitrogen to            which they are both attached to form a 2-6 membered            carbocyclic ring, wherein one or two of the ring carbon            atoms is replaced by a nitrogen, oxygen or sulfur, and the            carbocyclic is optionally substituted with one or more C₁₋₆            alkyl,    -   (g) represents —C(═O)—RC, S(O)_(n)—R^(C); C₅₋₁₀ heterocyclyl,        and C₆₋₁₀ aryl, said heterocyclyl and aryl optionally        substituted with 1 to 3 groups of R^(C); and wherein R^(C) is        selected from the group consisting of        -   (i) hydrogen,        -   (ii) —C₁₋₆ alkyl,        -   (iii) —O—C₁₋₆ alkyl,        -   (iv) CF₃,        -   (v) halogen,        -   (vi) cyano,    -   (h) CF₃,        n is 0, 1 or 2.

In one embodiment, the invention is directed to methods of treating apatient (preferably a human) for diseases in which the M1 receptor isinvolved, such as Alzheimer's Disease, cognitive impairment,schizophrenia, pain disorders and sleep disorders, by administering tothe patient a therapeutically effective amount of a compound of generalformula (I).

The invention is also directed to the use of a compound of formula (I)for treating diseases or disorders in which the M1 receptor is involved,such as Alzheimer's disease, cognitive impairment, schizophrenia, paindisorders and sleep disorders.

The invention is also directed to medicaments or pharmaceuticalcompositions for treating diseases or disorders in which the M1 receptoris involved, such as Alzheimer's disease, cognitive impairment,schizophrenia, pain disorders and sleep disorders, which comprise acompound of formula (I) and a pharmaceutically acceptable carrier.

The invention is further directed to a method for the manufacture of amedicament or a composition for treating diseases or disorders in whichthe M1 receptor is involved, such as Alzheimer's disease, cognitiveimpairment, schizophrenia, pain disorders and sleep disorders,comprising combining a compound of formula (I) with one or morepharmaceutically acceptable carriers.

An aspect of this invention is realized when R¹ is —NR²R³ and all othervariables are as originally described.

Another aspect of this invention is realized when R¹ is a nitrogencontaining C₅₋₁₀ heterocyclyl; wherein said heterocyclyl is optionallysubstituted with one or more of R^(a). A subembodiment of this inventionis realized when the heterocyclyl includes oxo substitutions on thering. Still another sub-embodiment of this invention is realized when R¹is selected from the group consisting of piperazinyl, piperidinyl,azepinyl, tetrahydroisoquinolinyl, tetrahydroquinolinyl, pyrrolidinyl,oxopiperazinyl, oxopiperidinyl, and oxopyrrolidinyl. Yet anothersub-embodiment of this invention is realized when R1 is oxopiperazinyl,piperazinyl, and piperidinyl.

Another aspect of the invention is realized when R^(a) is selected fromthe group consisting of cyano, halogen, —C₁₋₆ alkyl, —O—C₁₋₆ alkyl, CF₃,C₅₋₁₀ heterocyclyl, C₆₋₁₀ aryl, said heterocyclyl, aryl optionallysubstituted with 1 to 3 groups of R^(C).

Within the genus of compounds of formula (I), there is a sub-genus ofcompounds of formula (II):

or a pharmaceutically acceptable salt thereof wherein R^(a) is selectedfrom the group consisting of cyano, halogen, —C₁₋₆ alkyl, —O—C₁₋₆ alkyl,CF₃, C₅₋₁₀ heterocyclyl, C₆₋₁₀ aryl, said heterocyclyl, aryl optionallysubstituted with 1 to 3 groups of R^(C). A sub-embodiment of theinvention of formula II is realized when R^(a) is selected from thegroup consisting of cyano, fluoro, chloro, bromo, iodo, methoxy, CF₃,methyl, ethyl, propyl, butyl and optionally substituted phenyl, pyridyl,pyrazolyl, and imidazolyl.

Within the genus of compounds of formula (I), there is a sub-genus ofcompounds of formula (III):

or a pharmaceutically acceptable salt thereof wherein R^(a) is selectedfrom the group consisting of of cyano, halogen, —C₁₋₆ alkyl, —O—C₁₋₆alkyl, CF₃, C₅₋₁₀ heterocyclyl, C₆₋₁₀ aryl, said heterocyclyl, aryloptionally substituted with 1 to 3 groups of R^(C) and A is C₅₋₁₀heterocyclyl, or C₆₋₁₀ aryl, said heterocyclyl, aryl optionallysubstituted with 1 to 2 groups of R^(a). A sub-embodiment of theinvention of formula III is realized when R^(a) is selected from thegroup consisting of cyano, fluoro, chloro, bromo, iodo, methoxy, CF₃,methyl, ethyl, propyl, butyl and optionally substituted phenyl, pyridyl,pyrazolyl, and imidazolyl and A is selected from the group consisting ofphenyl, pyridyl, pyrazolyl, and imidazolyl, said phenyl, pyridyl,pyrazolyl, and imidazolyl optionally substituted with 0 to 2 groups ofR^(a).

Examples of compounds of formula (I) are:

-   1-{[2-(2-fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizin-5-yl]methyl}-4-(4-methylpyridin-2-yl)piperidine-4-carbonitrile;-   2-(2-fluorophenyl)-5-{[4-(1-methyl-1H-pyrazol-4-yl)-3-oxopiperazin-1-yl]methyl}pyrazolo[4,3-c]quinolizin-3(2H)-one;-   2-(2-fluorophenyl)-5-{[1-(pyridin-4-yl)-3,4-dihydroisoquinolin-2(1H)-yl]methyl}pyrazolo[4,3-c]quinolizin-3(2H)-one,-   1-{[2-(2-fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizin-5-yl]methyl}-4-(4-methoxypyridin-2-yl)piperidine-4-carbonitrile,-   2-(2-fluorophenyl)-5-({4-[4-(trifluoromethyl)phenyl]piperidin-1-yl}methyl)pyrazolo[4,3-yl)pyrazolo[4,3-c]quinolizin-3(2H)-one,-   1-{[2-(2-fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-e]quinolizin-5-yl]methyl}-4-phenylpiperidine-4-carbonitrile,-   4-(4-{[2-(2-fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizin-5-yl]-methyl}piperazin-1-yl)benzonitrile,-   2-(2-fluorophenyl)-5-{[4-(1-methyl-1H-pyrazol-4-yl)piperazin-1-yl]methyl}pyrazolo[4,3-c]quinolizin-3(2H)-one,-   5-[(4,4-difluoropiperidin-1-yl)methyl]-2-(2-fluorophenyl)pyrazolo[4,3-c]quinolizin-3(2H)-one,-   4-fluoro-1-{[2-(2-fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizin-5-yl]methyl}piperidine-4-carbonitrile,    and pharmaceutically acceptable salts thereof.

The invention is also directed to methods of treating a patient(preferably a human) for diseases or disorders in which the M1 receptoris involved, such as Alzheimer's Disease, cognitive impairment,schizophrenia, pain disorders and sleep disorders, by administering tothe patient a therapeutically effective amount of a compound of formulae(I), (II) and (III), or a pharmaceutically acceptable salt thereof.

The invention is also directed to the use of a compound of formulae (I),(II) and (III), for treating a disease or disorder in which the M1receptor is involved, such as Alzheimer's Disease, cognitive impairment,schizophrenia, pain disorders and sleep disorders, by administering tothe patient a compound of formulae (I), (II) and (III), or apharmaceutically acceptable salt thereof.

The invention is also directed to medicaments or pharmaceuticalcompositions for the treatment of diseases or disorders in a patient(preferably a human) in which the M1 receptor is involved, such asAlzheimer's Disease, cognitive impairment, schizophrenia, paindisorders, and sleep disorders, which comprise a compound of formulae(I), (II) and (III), or a pharmaceutically acceptable salt thereof, anda pharmaceutically acceptable carrier.

The invention is also directed to a method for the manufacture of amedicament or a pharmaceutical composition for treating diseases inwhich M1 receptor is involved, such as Alzheimer's Disease, cognitiveimpairment, schizophrenia, pain disorders, and sleep disorders,comprising combining a compound of formulae (I), (II) and (III), or apharmaceutically acceptable salt thereof, with a pharmaceuticallyacceptable carrier.

The invention also encompasses a pharmaceutical composition comprising acompound of Formula I, II, or III in combination with a pharmaceuticallyacceptable carrier.

The invention also encompasses a method for treating a neurological orpsychiatric disorder associated with glutamate dysfunction in a patientin need thereof comprising administering to the patient atherapeutically effective amount of a compound of Formula I. Theinvention also encompasses this method wherein the neurological orpsychiatric disorder associated with glutamate dysfunction isschizophrenia.

When any variable (e.g. aryl, heterocycle, R¹, R⁵ etc.) occurs more thanone time in any constituent, its definition on each occurrence isindependent at every other occurrence. Also, combinations ofsubstituents/or variables are permissible only if such combinationsresult in stable compounds.

As used herein, “alkyl” encompasses groups having the prefix “alk” suchas, for example, alkoxy, alkanoyl, alkenyl, and alkynyl and means carbonchains which may be linear or branched or combinations thereof. Examplesof alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, sec-and tert-butyl, pentyl, hexyl, and heptyl. “Alkenyl” refers to ahydrocarbon radical straight, branched or cyclic containing from 2 to 10carbon atoms and at least one carbon to carbon double bond. Preferredalkenyl groups include ethenyl, propenyl, butenyl and cyclohexenyl.Preferably, alkenyl is C₂-C₆ alkenyl. Preferred alkynyls are C₂-C₆alkynyl.

“Alkenyl,” “alkynyl” and other like terms include carbon chainscontaining at least one unsaturated C—C bond.

As used herein, “fluoroalkyl” refers to an alkyl substituent asdescribed herein containing at least one fluorine substituent.

The term “cycloalkyl” refers to a saturated hydrocarbon containing onering having a specified number of carbon atoms. Examples of cycloalkylinclude cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

The term “C₁₋₆” includes alkyls containing 6, 5, 4, 3, 2, or 1 carbonatoms

The term “alkoxy” as used herein, alone or in combination, includes analkyl group connected to the oxy connecting atom. The term “alkoxy” alsoincludes alkyl ether groups, where the term ‘alkyl’ is defined above,and ‘ether’ means two alkyl groups with an oxygen atom between them.Examples of suitable alkoxy groups include methoxy, ethoxy, n-propoxy,i-propoxy, n-butoxy, s-butoxy, t-butoxy, methoxymethane (also referredto as ‘dimethyl ether’), and methoxyethane (also referred to as ‘ethylmethyl ether’).

As used herein, “aryl” is intended to mean any stable monocyclic orbicyclic carbon ring of up to 7 members in each ring, wherein at leastone ring is aromatic. Examples of such aryl elements include phenyl,napthyl, tetrahydronapthyl, indanyl, or biphenyl.

The term heterocycle, heterocyclyl, or heterocyclic, as used herein,represents a stable 5- to 7-membered monocyclic or stable 8- to11-membered bicyclic heterocyclic ring which is either saturated orunsaturated, and which consists of carbon atoms and from one to fourheteroatoms selected from the group consisting of N, O, and S, andincluding any bicyclic group in which any of the above-definedheterocyclic rings is fused to a benzene ring. The heterocyclic ring maybe attached at any heteroatom or carbon atom which results in thecreation of a stable structure. The term heterocycle or heterocyclicincludes heteroaryl moieties. Examples of such heterocyclic elementsinclude, but are not limited to, azepinyl, benzimidazolyl,benzisoxazolyl, benzofurazanyl, benzopyranyl, benzothiopyranyl,benzofuryl, benzothiazolyl, benzothienyl, benzoxazolyl, chromanyl,cinnolinyl, dihydrobenzofuryl, dihydrobenzothienyl,dihydrobenzothiopyranyl, dihydrobenzothiopyranyl sulfone,1,3-dioxolanyl, furyl, imidazolidinyl, imidazolinyl, imidazolyl,indolinyl, indolyl, isochromanyl, isoindolinyl, isoquinolinyl,isothiazolidinyl, isothiazolyl, isothiazolidinyl, morpholinyl,naphthyridinyl, oxadiazolyl, 2-oxoazepinyl, oxazolyl, 2-oxopiperazinyl,2-oxopiperdinyl, 2-oxopyrrolidinyl, piperidyl, piperazinyl, pyridyl,pyrazinyl, pyrazolidinyl, pyrazolyl, pyridazinyl, pyrimidinyl,pyrrolidinyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl,tetrahydrofuryl, tetrahydroisoquinolinyl, tetrahydroquinolinyl,thiamorpholinyl, thiamorpholinyl sulfoxide, thiazolyl, thiazolinyl,thienofuryl, thienothienyl, thienyl and triazolyl.

In certain embodiments, the heterocyclic group is a heteroaryl group.

In certain other embodiments, the heterocyclic group is fused to an arylor heteroaryl group. Examples of such fused heterocycles include,without limitation, tetrahydroquinolinyl and dihydrobenzofuranyl.

The term “heteroaryl”, as used herein except where noted, represents astable 5- to 7-membered monocyclic- or stable 9- to 10-membered fusedbicyclic heterocyclic ring system which contains an aromatic ring, anyring of which may be saturated, such as piperidinyl, partiallysaturated, or unsaturated, such as pyridinyl, and which consists ofcarbon atoms and from one to four heteroatoms selected from the groupconsisting of N, O and S, and wherein the nitrogen and sulfurheteroatoms may optionally be oxidized, and the nitrogen heteroatom mayoptionally be quaternized, and including any bicyclic group in which anyof the above-defined heterocyclic rings is fused to a benzene ring. Theheterocyclic ring may be attached at any heteroatom or carbon atom whichresults in the creation of a stable structure. Examples of suchheteroaryl groups include, but are not limited to, benzimidazole,benzisothiazole, benzisoxazole, benzofuran, benzothiazole,benzothiophene, benzotriazole, benzoxazole, carboline, cinnoline, furan,furazan, imidazole, indazole, indole, indolizine, isoquinoline,isothiazole, isoxazole, naphthyridine, oxadiazole, oxazole, phthalazine,pteridine, purine, pyran, pyrazine, pyrazole, pyridazine, pyridine,pyrimidine, pyrrole, quinazoline, quinoline, quinoxaline, tetrazole,thiadiazole, thiazole, thiophene, triazine, triazole, and N-oxidesthereof.

The term “heteroatom” means O, S or N, selected on an independent basis.

A moiety that is substituted is one in which one or more hydrogens havebeen independently replaced with another chemical substituent. As anon-limiting example, substituted phenyls include 2-flurophenyl,3,4-dichlorophenyl, 3-chloro-4-fluoro-phenyl, 2,4fluor-3-propylphenyl.As another non-limiting example, substituted n-octyls include 2,4dimethyl-5-ethyl-octyl and 3-cyclopentyloctyl. Included within thisdefinition are methylenes (—CH₂—) substituted with oxygen to formcarbonyl (—CO—).

Unless otherwise stated, as employed herein, when a moiety (e.g.,cycloalkyl, hydrocarbyl, aryl, alkyl, heteroaryl, heterocyclic, urea,etc.) is described as “optionally substituted” it is meant that thegroup optionally has from one to four, preferably from one to three,more preferably one or two, non-hydrogen substituents. Suitablesubstituents include, without limitation, halo, hydroxy, oxo (e.g., anannular —CH— substituted with oxo is —C(O)—), nitro, halohydrocarbyl,hydrocarbyl, aryl, aralkyl, alkoxy, aryloxy, amino, acylamino,alkylcarbamoyl, arylcarbamoyl, aminoalkyl, acyl, carboxy, hydroxyalkyl,alkanesulfonyl, arenesulfonyl, alkanesulfonamido, arenesulfonamido,aralkylsulfonamido, alkylcarbonyl, acyloxy, cyano, and ureido groups.Preferred substituents, which are themselves not further substituted(unless expressly stated otherwise) are:

-   -   (a) halo, cyano, oxo, carboxy, formyl, nitro, amino, amidino,        guanidino, and    -   (b) C₁-C₆ alkyl or alkenyl or arylalkyl imino, carbamoyl, azido,        carboxamido, mercapto, hydroxy, hydroxyalkyl, alkylaryl,        arylalkyl, C₁-C₈ alkyl, SO₂CF₃, CF₃, SO₂Me, C₁-C₈ alkenyl, C₁-C₈        alkoxy, C₁-C₈ alkoxycarbonyl, aryloxycarbonyl, C₂-C₈ acyl, C₂-C₈        acylamino, C₁-C₈ alkylthio, arylalkylthio, arylthio,        C₁-C₈alkylsulfinyl, arylalkylsulfnyl, arylsulfnyl, C₁-C₈        alkylsulfonyl, arylalkylsulfonyl, arylsulfonyl, C₀-C₆        N-alkylcarbamoyl, C₂-C₁₅ N,N dialkylcarbamoyl, C₃-C₇ cycloalkyl,        aroyl, aryloxy, arylalkyl ether, aryl, aryl fused to a        cycloalkyl or heterocycle or another aryl ring, C₃-C₇        heterocycle, or any of these rings fused or spiro-fused to a        cycloalkyl, heterocyclyl, or aryl, wherein each of the foregoing        is further optionally substituted with one more moieties listed        in (a), above.

“Halogen” refers to fluorine, chlorine, bromine and iodine.

The term “mammal” “mammalian” or “mammals” includes humans, as well asanimals, such as dogs, cats, horses, pigs and cattle.

All patents, patent applications and publications cited herein, whethersupra or infra, are hereby incorporated by reference in their entiretyand are deemed representative of the prevailing state of the art.

As used in this specification and the appended claims, the singularforms “a,” “an” and “the” include plural references unless the contentclearly dictates otherwise. Thus, for example, reference to “a primer”includes two or more such primers, reference to “an amino acid” includesmore than one such amino acid, and the like.

Compounds described herein may contain one or more double bonds and maythus give rise to cis/trans isomers as well as other conformationalisomers. The present invention includes all such possible isomers aswell as mixtures of such isomers unless specifically stated otherwise.

The compounds of the present invention may contain one or moreasymmetric centers and may thus occur as racemates, racemic mixtures,single enantiomers, diastereomeric mixtures, and individualdiastereomers.

In the compounds of generic Formula I, the atoms may exhibit theirnatural isotopic abundances, or one or more of the atoms may beartificially enriched in a particular isotope having the same atomicnumber, but an atomic mass or mass number different from the atomic massor mass number predominantly found in nature. The present invention ismeant to include all suitable isotopic variations of the compounds ofgeneric Formula I. For example, different isotopic forms of hydrogen (H)include protium (¹H) and deuterium (²H). Protium is the predominanthydrogen isotope found in nature. Enriching for deuterium may affordcertain therapeutic advantages, such as increasing in vivo half-life orreducing dosage requirements, or may provide a compound useful as astandard for characterization of biological samples.Isotopically-enriched compounds within generic Formula I can be preparedwithout undue experimentation by conventional techniques well known tothose skilled in the art or by processes analogous to those described inthe Schemes and Examples herein using appropriate isotopically-enrichedreagents and/or intermediates.

It will be understood that, as used herein, references to the compoundsof structural formula I are meant to also include the pharmaceuticallyacceptable salts, and also salts that are not pharmaceuticallyacceptable when they are used as precursors to the free compounds or inother synthetic manipulations.

The compounds of the present invention may be administered in the formof a pharmaceutically acceptable salt. The twit “pharmaceuticallyacceptable salts” refers to salts prepared from pharmaceuticallyacceptable non-toxic bases or acids. When the compound of the presentinvention is acidic, its corresponding salt can be conveniently preparedfrom pharmaceutically acceptable non-toxic bases, including inorganicbases and organic bases. Salts derived from such inorganic bases includealuminum, ammonium, calcium, copper (ic and ous), ferric, ferrous,lithium, magnesium, manganese (ic and ous), potassium, sodium, zinc andthe like salts. Salts derived from pharmaceutically acceptable organicnon-toxic bases include salts of primary, secondary, and tertiaryamines, as well as cyclic amines and substituted amines such asnaturally occurring and synthesized substituted amines. Otherpharmaceutically acceptable organic non-toxic bases from which salts canbe formed include ion exchange resins such as, for example, arginine,betaine, caffeine, choline, N,N′-dibenzylethylenediamine, diethylamine,2-diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine,ethylenediamine, N-ethylmorpholine, N-ethylpiperidine, glucarnine,glucosamine, histidine, hydrabamine, isopropylamine, lysine,methylglucamine, morpholine, piperazine, piperidine, polyamine resins,procaine, purines, theobromine, triethylamine, trimethylamine,tripropylamine, and tromethamine.

When the compound of the present invention is basic, its correspondingsalt can be conveniently prepared from pharmaceutically acceptablenon-toxic acids, including inorganic and organic acids. Such acidsinclude, for example, acetic, benzenesulfonic, benzoic, camphorsulfonic,citric, ethanesulfonic, fumaric, gluconic, glutamic, hydrobromic,hydrochloric, isethionic, lactic, maleic, malic, mandelic,methanesulfonic, mucic, nitric, pamoic, pantothenic, phosphoric,succinic, sulfuric, tartaric, p-toluenesulfonic acid and the like.

The compounds of the invention may be prepared according to thefollowing reaction Schemes, in which variables are as defined before orare derived, using readily available starting materials, from reagentsand conventional synthetic procedures. It is also possible to usevariants which are themselves known to those of ordinary skill inorganic synthesis art, but are not mentioned in greater detail.

The present invention also provides a method for the synthesis ofcompounds useful as intermediates in the preparation of compounds of theinvention.

During any of the above synthetic sequences it may be necessary ordesirable to protect sensitive or reactive groups on any of themolecules concerned. This may be achieved by means of conventionalprotecting groups, such as those described in Protective Groups inOrganic Chemistry, ed. J. F. W. McOmie, Plenum Press, 1973, and T. W.Greene & P/G. M. Wuts, Protective Groups in Organic Synthesis, JohnWiley & Sons, 1999. The protecting groups may be removed at a convenientsequent stage using methods known from the art.

Specific embodiments of the compounds of the invention, and methods ofmaking them, are described in the Examples herein.

The term “substantially pure” means that the isolated material is atleast 90% pure, and preferably 95% pure, and even more preferably 99%pure as assayed by analytical techniques known in the art.

As used herein, the term “muscarinic M1 receptor” refers to one of thefive subtypes of the muscarinic acetylcholine receptor, which is fromthe superfamily of G-protein coupled receptors. The family of muscarinicreceptors is described, for example, in Pharmacol Ther, 1993,58:319-379; Eur J Pharmacol, 1996, 295:93-102, and Mol Pharmacol, 2002,61:1297-1302. The muscarinic receptors are known to contain one or moreallosteric sites, which may alter the affinity with which muscarinicligands bind to the primary binding or orthosteric sites. See, e.g., S.Lazareno et al, Mol Pharmacol, 2002, 62:6, 1491-1505.

As used herein, the terms “positive allosteric modulator” and“allosteric potentiator” are used interchangeably, and refer to a ligandwhich interacts with an allosteric site of a receptor to activate theprimary binding site. The compounds of the invention are positiveallosteric modulators of the muscarinic M1 receptor. For example, amodulator or potentiator may directly or indirectly augment the responseproduced by the endogenous ligand (such as acetylcholine or xanomeline)at the orthosteric site of the muscarinic M1 receptor in an animal, inparticular, a human.

The actions of ligands at allosteric receptor sites may also beunderstood according to the “allosteric ternary complex model,” as knownby those skilled in the art.

The allosteric ternary complex model is described with respect to thefamily of muscarinic receptors in Birdsall et al, Life Sciences, 2001,68:2517-2524. For a general description of the role of allostericbinding sites, see Christopoulos, Nature Reviews: Drug Discovery, 2002,1:198-210.

It is believed that the compounds of the invention bind to an allostericbinding site that is distinct from the orthosteric acetylcholine site ofthe muscarinic M1 receptor, thereby augmenting the response produced bythe endogenous ligand acetylcholine at the orthosteric site of the M1receptor. It is also believed that the compounds of the invention bindto an allosteric site which is distinct from the xanomeline site of themuscarinic M1 receptor, thereby augmenting the response produced by theendogenous ligand xanomeline at the orthosteric site of the M1 receptor.

The present invention is directed to the use of the compounds offormulae (I) to (III) disclosed herein as M1 allosteric modulators in apatient or subject such as a mammal in need of such activity, comprisingthe administration of an effective amount of the compound. In additionto humans, a variety of other mammals can be treated according to themethod of the present invention.

The compounds of the present invention have utility in treating orameliorating Alzheimer's disease. The compounds may also be useful intreating or ameliorating other diseases mediated by the muscarinic M1receptor, such as schizophrenia, sleep disorders, pain disorders(including acute pain, inflammatory pain and neuropathic pain) andcognitive disorders (including mild cognitive impairment). Otherconditions that may be treated by the compounds of the invention includeParkinson's Disease, pulmonary hypertension, chronic obstructivepulmonary disease (COPD), asthma, urinary incontinence, glaucoma,schizophrenia, Trisomy 21 (Down Syndrome), cerebral amyloid angiopathy,degenerative dementia, Hereditary Cerebral Hemorrhage with Amyloidosisof the Dutch-Type (HCHWA-D), Creutzfeld-Jakob disease, prion disorders,amyotrophic lateral sclerosis, progressive supranuclear palsy, headtrauma, stroke, pancreatitis, inclusion body myositis, other peripheralamyloidoses, diabetes, autism and atherosclerosis.

In preferred embodiments, the compounds of the invention are useful intreating Alzheimer's Disease, cognitive disorders, schizophrenia, paindisorders and sleep disorders. For example, the compounds may be usefulfor the prevention of dementia of the Alzheimer's type, as well as forthe treatment of early stage, intermediate stage or late stage dementiaof the Alzheimer's type.

Potential schizophrenia conditions or disorders for which the compoundsof the invention may be useful include one or more of the followingconditions or diseases: schizophrenia or psychosis includingschizophrenia (paranoid, disorganized, catatonic or undifferentiated),schizophreniform disorder, schizoaffective disorder, delusionaldisorder, brief psychotic disorder, shared psychotic disorder, psychoticdisorder due to a general medical condition and substance-induced ordrug-induced (phencyclidine, ketanine and other dissociativeanaesthetics, amphetamine and other psychostimulants and cocaine)psychosispsychotic disorder, psychosis associated with affectivedisorders, brief reactive psychosis, schizoaffective psychosis,“schizophrenia-spectrum” disorders such as schizoid or schizotypalpersonality disorders, or illness associated with psychosis (such asmajor depression, manic depressive (bipolar) disorder, Alzheimer'sdisease and post-traumatic stress syndrome), including both the positiveand the negative symptoms of schizophrenia and other psychoses;cognitive disorders including dementia (associated with Alzheimer'sdisease, ischemia, multi-infarct dementia, trauma, vascular problems orstroke, HIV disease, Parkinson's disease, Huntington's disease, Pick'sdisease, Creutzfeldt-Jacob disease, perinatal hypoxia, other generalmedical conditions or substance abuse); delirium, amnestic disorders orage related cognitive decline.

In another specific embodiment, the present invention provides a methodfor treating schizophrenia or psychosis comprising administering to apatient in need thereof an effective amount of a compound of the presentinvention. Particular schizophrenia or psychosis pathologies areparanoid, disorganized, catatonic or undifferentiated schizophrenia andsubstance-induced psychotic disorder. At present, the text revision ofthe fourth edition of the Diagnostic and Statistical Manual of MentalDisorders (DSM-IV-TR) (2000, American Psychiatric Association,Washington D.C.) provides a diagnostic tool that includes paranoid,disorganized, catatonic or undifferentiated schizophrenia andsubstance-induced psychotic disorder. As used herein, the term“schizophrenia or psychosis” includes treatment of those mentaldisorders as described in DSM-IV-TR. The skilled artisan will recognizethat there are alternative nomenclatures, nosologies and classificationsystems for mental disorders, and that these systems evolve with medicaland scientific progress. Thus the term “schizophrenia or psychosis” isintended to include like disorders that are described in otherdiagnostic sources.

Examples of combinations of the compounds include combinations withagents for the treatment of schizophrenia, for example in combinationwith sedatives, hypnotics, anxiolytics, antipsychotics, antianxietyagents, cyclopyrrolones, imidazopyridines, pyrazolopyrimidines, minortranquilizers, melatonin agonists and antagonists, melatonergic agents,benzodiazepines, barbiturates, 5HT-2 antagonists, and the like, such as:adinazolam, allobarbital, alonimid, aiprazolam, amisulpride,amitriptyline, amobarbital, amoxapine, aripiprazole, bentazepam,benzoctamine, brotizolam, bupropion, busprione, butabarbital,butalbital, capuride, carbocloral, chloral betaine, chloral hydrate,clomipramine, clonazepam, cloperidone, clorazepate, chlordiazepoxide,clorethate, chlorpromazine, clozapine, cyprazepam, desipramine,dexclamol, diazepam, dichloralphenazone, divalproex, diphenhydramine,doxepin, estazolam, ethchlorvynol, etomidate, fenobam, flunitrazepam,flupentixol, fluphenazine, flurazepam, fluvoxamine, fluoxetine,fosazepam, glutethimide, halazepam, haloperidol, hydroxyzine,imipramine, lithium, lorazepam, lormetazepam, maprotiline, mecloqualone,melatonin, mephobarbital, meprobamate, methaqualone, midaflur,midazolam, nefazodone, nisobamate, nitrazepam, nortriptyline,olanzapine, oxazepam, paraldehyde, paroxetine, pentobarbital, perlapine,perphenazine, phenelzine, phenobarbital, prazepam, promethazine,propofol, protriptyline, quazepam, quetiapine, reclazepam, risperidone,roletamide, secobarbital, sertraline, suproelone, temazepam,thioridazine, thiothixene, tracazolate, tranylcypromaine, trazodone,triazolam, trepipam, tricetamide, triclofos, trifluoperazine,trimetozine, trimipramine, uldazepain, venlafaxine, zaleplon,ziprasidone, zolazepam, zolpidem, and salts thereof, and combinationsthereof, and the like, or the subject compound may be administered inconjunction with the use of physical methods such as with light therapyor electrical stimulation.

In another embodiment, the subject compound may be employed incombination with levodopa (with or without a selective extracerebraldecarboxylase inhibitor such as carbidopa or benserazide),anticholinergics such as biperiden (optionally as its hydrochloride orlactate salt) and trihexyphenidyl (benzhexol) hydrochloride, COMTinhibitors such as entacapone, MOA-B inhibitors, antioxidants, A2aadenosine receptor antagonists, cholinergic agonists, NMDA receptorantagonists, serotonin receptor antagonists and dopamine receptoragonists such as alentemol, bromocriptine, fenoldopam, lisuride,naxagolide, pergolide and pramipexole. It will be appreciated that thedopamine agonist may be in the form of a pharmaceutically acceptablesalt, for example, alentemol hydrobromide, bromocriptine mesylate,fenoldopam mesylate, naxagolide hydrochloride and pergolide mesylate.

In another embodiment, the subject compound may be employed incombination with a compound from the phenothiazine, thioxanthene,heterocyclic dibenzazepine, butyrophenone, diphenylbutylpiperidine andindolone classes of neuroleptic agent. Suitable examples ofphenothiazines include chlorpromazine, mesoridazine, thioridazine,acetophenazine, fluphenazine, perphenazine and trifluoperazine. Suitableexamples of thioxanthenes include chlorprothixene and thiothixene. Anexample of a dibenzazepine is clozapine. An example of a butyrophenoneis haloperidol. An example of a diphenylbutylpiperidine is pimozide. Anexample of an indolone is molindolone. Other neuroleptic agents includeloxapine, sulpiride and risperidone. It will be appreciated that theneuroleptic agents when used in combination with the subject compoundmay be in the faun of a pharmaceutically acceptable salt, for example,chlorpromazine hydrochloride, mesoridazine besylate, thioridazinehydrochloride, acetophenazine maleate, fluphenazine hydrochloride,flurphenazine enathate, fluphenazine decanoate, trifluoperazinehydrochloride, thiothixene hydrochloride, haloperidol decanoate,loxapine succinate and molindone hydrochloride. Perphenazine,chlorprothixene, clozapine, haloperidol, pimozide and risperidone arecommonly used in a non-salt form. Thus, the subject compound may beemployed in combination with acetophenazine, alentemol, aripiprazole,amisuipride, benzhexol, bromocriptine, biperiden, chlorpromazine,chlorprothixene, clozapine, diazepam, fenoldopam, fluphenazine,haloperidol, levodopa, levodopa with benserazide, levodopa withcarbidopa, lisuride, loxapine, mesoridazine, molindolone, naxagolide,olanzapine, pergolide, perphenazine, pimozide, pramipexole, quetiapine,risperidone, sulpiride, tetrabenazine, frihexyphenidyl, thioridazine,thiothixene, trifluoperazine or ziprasidone.

Potential sleep conditions or disorders for which the compounds of theinvention may be useful include enhancing sleep quality; improving sleepquality; augmenting sleep maintenance; increasing the value which iscalculated from the time that a subject sleeps divided by the time thata subject is attempting to sleep; decreasing sleep latency or onset (thetime it takes to fall asleep); decreasing difficulties in fallingasleep; increasing sleep continuity; decreasing the number of awakeningsduring sleep; decreasing nocturnal arousals; decreasing the time spentawake following the initial onset of sleep; increasing the total amountof sleep; reducing the fragmentation of sleep; altering the timing,frequency or duration of REM sleep bouts; altering the timing, frequencyor duration of slow wave (i.e. stages 3 or 4) sleep bouts; increasingthe amount and percentage of stage 2 sleep; promoting slow wave sleep;enhancing EEG-delta activity during sleep; increasing daytime alertness;reducing daytime drowsiness; treating or reducing excessive daytimesleepiness; insomnia; hypersomnia; narcolepsy; interrupted sleep; sleepapnea; wakefulness; nocturnal myoclonus; REM sleep interruptions;jet-lag; shift workers' sleep disturbances; dyssomnias; night terror;insomnias associated with depression, emotional/mood disorders, as wellas sleep walking and enuresis, and sleep disorders which accompanyaging; Alzheimer's sundowning; conditions associated with circadianrhythmicity as well as mental and physical disorders associated withtravel across time zones and with rotating shift-work schedules;conditions due to drugs which cause reductions in REM sleep as a sideeffect; syndromes which are manifested by non-restorative sleep andmuscle pain or sleep apnea which is associated with respiratorydisturbances during sleep; and conditions which result from a diminishedquality of sleep.

Pain disorders for which the compounds of the invention may be usefulinclude neuropathic pain (such as postherpetic neuralgia, nerve injury,the “dynias”, e.g., vulvodynia, phantom limb pain, root avulsions,painful diabetic neuropathy, painful traumatic mononeuropathy, painfulpolyneuropathy); central pain syndromes (potentially caused by virtuallyany lesion at any level of the nervous system); postsurgical painsyndromes (eg, postmastectomy syndrome, postthoracotomy syndrome, stumppain); bone and joint pain (osteoarthritis), repetitive motion pain,dental pain, cancer pain, myofascial pain (muscular injury,fibromyalgia); perioperative pain (general surgery, gynecological),chronic pain, dysmennorhea, as well as pain associated with angina, andinflammatory pain of varied origins (e.g. osteoarthritis, rheumatoidarthritis, rheumatic disease, teno-synovitis and gout), headache,migraine and cluster headache, headache, primary hyperalgesia, secondaryhyperalgesia, primary allodynia, secondary allodynia, or other paincaused by central sensitization.

Compounds of the invention may also be used to treat or preventdyskinesias. Furthermore, compounds of the invention may be used todecrease tolerance and/or dependence to opioid treatment of pain, andfor treatment of withdrawal syndrome of e.g., alcohol, opioids, andcocaine.

The subject or patient to whom the compounds of the present invention isadministered is generally a human being, male or female, in whom M1allosteric modulation is desired, but may also encompass other mammals,such as dogs, cats, mice, rats, cattle, horses, sheep, rabbits, monkeys,chimpanzees or other apes or primates, for which treatment of the abovenoted disorders is desired.

The compounds of the present invention may be used in combination withone or more other drugs in the treatment of diseases or conditions forwhich the compounds of the present invention have utility, where thecombination of the drugs together are safer or more effective thaneither drug alone. Additionally, the compounds of the present inventionmay be used in combination with one or more other drugs that treat,prevent, control, ameliorate, or reduce the risk of side effects ortoxicity of the compounds of the present invention. Such other drugs maybe administered, by a route and in an amount commonly used therefor,contemporaneously or sequentially with the compounds of the presentinvention. Accordingly, the pharmaceutical compositions of the presentinvention include those that contain one or more other activeingredients, in addition to the compounds of the present invention. Thecombinations may be administered as part of a unit dosage formcombination product, or as a kit or treatment protocol wherein one ormore additional drugs are administered in separate dosage forms as partof a treatment regimen.

Examples of combinations of the compounds of the present inventioninclude combinations with anti-Alzheimer's Disease agents, for examplebeta-secretase inhibitors; alpha 7 nicotinic agonists, such as ABT089,SSR180711 and MEM63908; ADAM 10 ligands or activators; gamma-secretaseinhibitors, such as LY450139 and TAK 070; gamma secretase modulators;tau phosphorylation inhibitors; glycine transport inhibitors; LXR βagonists; ApoE4 conformational modulators; NR2B antagonists; androgenreceptor modulators; blockers of Aβ oligomer formation; 5-HT4 agonists,such as PRX-03140; 5-HT6 antagonists, such as GSK 742467, SGS-518,FK-962, SL-65.0155, SRA-333 and xaliproden; 5-HT1a antagonists, such aslecozotan; p25/CDK5 inhibitors; NK1/NK3 receptor antagonists; COX-2inhibitors; HMG-CoA reductase inhibitors; NSAIDs including ibuprofen;vitamin E; anti-amyloid antibodies (including anti-amyloid humanizedmonoclonal antibodies), such as bapineuzumab, ACC001, CAD106, AZD3102,H12A11V1; anti-inflammatory compounds such as (R)-flurbiprofen,nitroflurbiprofen, ND-1251, VP-025, HT-0712 and EHT-202; PPAR gammaagonists, such as pioglitazone and rosiglitazone; CB-1 receptorantagonists or CB-1 receptor inverse agonists, such as AVE1625;antibiotics such as doxycycline and rifampin; N-methyl-D-aspartate(NMDA) receptor antagonists, such as memantine, neramexane and EVT101;cholinesterase inhibitors such as galantamine, rivastigmine, donepezil,tacrine, phenserine, ladostigil and ABT-089; growth hormonesecretagogues such as ibutamoren, ibutamoren mesylate, and capromorelin;histamine H₃ receptor antagonists such as ABT-834, ABT 829, GSK 189254and CEP16795; AMPA agonists or AMPA modulators, such as CX-717, LY451395, LY404187 and S-18986; PDE IV inhibitors, including MEM1414,HT0712 and AVE8112; GABA_(A) inverse agonists; GSK3β inhibitors,including AZD1080, SAR502250 and CEP16805; neuronal nicotinic agonists;selective M1 agonists; HDAC inhibitors; and microtubule affinityregulating kinase (MARK) ligands; or other drugs that affect receptorsor enzymes that either increase the efficacy, safety, convenience, orreduce unwanted side effects or toxicity of the compounds of the presentinvention.

Examples of combinations of the compounds include combinations withagents for the treatment of pain, for example non-steroidalanti-inflammatory agents, such as aspirin, diclofenac, duflunisal,fenoprofen, flurbiprofen, ibuprofen, indomethacin, ketoprofen,ketorolac, naproxen, oxaprozin, piroxicam, sulindac and tolmetin; COX-2inhibitors, such as celecoxib, rofecoxib, valdecoxib, 406381 and 644784;CB-2 agonists, such as 842166 and SAB378; VR-1 antagonists, such asAMG517, 705498, 782443, PAC20030, V114380 and A425619; bradykinin B1receptor antagonists, such as SSR240612 and NVPSAA164; sodium channelblockers and antagonists, such as VX409 and SP1860; nitric oxidesynthase (NOS) inhibitors (including iNOS and nNOS inhibitors), such asSD6010 and 274150; glycine site antagonists, including lacosamide;neuronal nicotinic agonists, such as ABT 894; NMDA antagonists, such asAZD4282; potassium channel openers; AMPA/kainate receptor antagonists;calcium channel blockers, such as ziconotide and NMED160; GABA-Areceptor IO modulators (e.g., a GABA-A receptor agonist); matrixmetalloprotease (MMP) inhibitors; thrombolytic agents; opioid analgesicssuch as codeine, fentanyl, hydromorphone, levorphanol, meperidine,methadone, morphine, oxycodone, oxymorphone, pentazocine, propoxyphene;neutrophil inhibitory factor (NIF); pramipexole, ropinirole;anticholinergics; amantadine; monoamine oxidase B15 (“MAO-B”)inhibitors; 5HT receptor agonists or antagonists; mGlu5 antagonists,such as AZD9272; alpha agonists, such as AGNXXJYY; neuronal nicotinicagonists, such as ABT894; NMDA receptor agonists or antagonists, such asAZD4282; NKI antagonists; selective serotonin reuptake inhibitors(“SSR1”) and/or selective serotonin and norepinephrine reuptakeinhibitors (“SSNRI”), such as duloxetine; tricyclic antidepressantdrugs, norepinephrine modulators; lithium; valproate; gabapentin;pregabalin; rizatriptan; zolmitriptan; naratriptan and sumatriptan.

The compounds of the present invention may be administered incombination with compounds useful for enhancing sleep quality andpreventing and treating sleep disorders and sleep disturbances,including e.g., sedatives, hypnotics, anxiolytics, antipsychotics,antianxiety agents, antihistamines, benzodiazepines, barbiturates,cyclopyrrolones, orexin antagonists, alpha-1 antagonists, GABA agonists,5HT-2 antagonists including 5HT-2A antagonists and 5HT-2A/2Cantagonists, histamine antagonists including histamine H3 antagonists,histamine H3 inverse agonists, imidazopyridines, minor tranquilizers,melatonin agonists and antagonists, melatonergic agents, other orexinantagonists, orexin agonists, prokineticin agonists and antagonists,pyrazolopyrimidines, T-type calcium channel antagonists,triazolopyridines, and the like, such as: adinazolam, allobarbital,alonimid, alprazolam, amitriptyline, amobarbital, amoxapine,armodafinil, APD-125, bentazepam, benzoctamine, brotizolam, bupropion,busprione, butabarbital, butalbital, capromorelin, capuride,carbocloral, chloral betaine, chloral hydrate, chlordiazepoxide,clomipramine, clonazepam, cloperidone, clorazepate, clorethate,clozapine, conazepam, cyprazepam, desipramine, dexclamol, diazepam,dichloralphenazone, divalproex, diphenhydramine, doxepin, EMD-281014,eplivanserin, estazolam, eszopiclone, ethchlorynol, etomidate, fenobam,flunitrazepam, flurazepam, fluvoxamine, fluoxetine, fosazepam,gaboxadol, glutethimide, halazepam, hydroxyzine, ibutamoren, imipramine,indiplon, lithium, lorazepam, lormetazepam, LY-156735, maprotiline,MDL-100907, mecloqualone, melatonin, mephobarbital, meprobamate,methaqualone, methyprylon, midaflur, midazolam, modafinil, nefazodone,NGD-2-73, nisobamate, nitrazepam, nortriptyline, oxazepam, paraldehyde,paroxetine, pentobarbital, perlapine, perphenazine, phenelzine,phenobarbital, prazepam, promethazine, propofol, protriptyline,quazepam, ramelteon, reclazepam, roletamide, secobarbital, sertraline,suproclone, TAK-375, temazepam, thioridazine, tiagabine, tracazolate,tranylcypromaine, trazodone, triazolam, trepipam, tricetamide,triclofos, trifluoperazine, trimetozine, trimipramine, uldazepam,venlafaxine, zaleplon, zolazepam, zopiclone, zolpidem, and saltsthereof, and combinations thereof, and the like, or the compound of thepresent invention may be administered in conjunction with the use ofphysical methods such as with light therapy or electrical stimulation.

The term “composition” as used herein is intended to encompass a productcomprising specified ingredients in predetermined amounts orproportions, as well as any product which results, directly orindirectly, from combination of the specified ingredients in thespecified amounts. This term in relation to pharmaceutical compositionsis intended to encompass a product comprising one or more activeingredients, and an optional carrier comprising inert ingredients, aswell as any product which results, directly or indirectly, fromcombination, complexation or aggregation of any two or more of theingredients, or from dissociation of one or more of the ingredients, orfrom other types of reactions or interactions of one or more of theingredients.

In general, pharmaceutical compositions are prepared by uniformly andintimately bringing the active ingredient into association with a liquidcarrier or a finely divided solid carrier or both, and then, ifnecessary, shaping the product into the desired formulation. In thepharmaceutical composition the active compound, which is a compound offormulae (I) to (VIII), is included in an amount sufficient to producethe desired effect upon the process or condition of diseases.Accordingly, the pharmaceutical compositions of the present inventionencompass any composition made by admixing a compound of the presentinvention and a pharmaceutically acceptable carrier.

The carrier may take a wide variety of forms depending on the form ofpreparation desired for administration, e.g., oral or parenteral(including intravenous). Thus, the pharmaceutical compositions of thepresent invention can be presented as discrete units suitable for oraladministration such as capsules, cachets or tablets each containing apredetermined amount of the active ingredient. Further, the compositionscan be presented as a powder, as granules, as a solution, as asuspension in an aqueous liquid, as a non-aqueous liquid, as anoil-in-water emulsion or as a water-in-oil liquid emulsion. In additionto the common dosage forms set out above, the compounds of theinvention, or pharmaceutically acceptable salts thereof; may also beadministered by controlled release means and/or delivery devices.

Pharmaceutical compositions intended for oral use may be preparedaccording to any method known to the art for the manufacture ofpharmaceutical compositions and such compositions may contain one ormore agents selected from the group consisting of sweetening agents,flavoring agents, coloring agents and preserving agents in order toprovide pharmaceutically elegant and palatable preparations. Tablets maycontain the active ingredient in admixture with non-toxicpharmaceutically acceptable excipients which are suitable for themanufacture of tablets. These excipients may be, for example, inertdiluents, such as calcium carbonate, sodium carbonate, lactose, calciumphosphate or sodium phosphate; granulating and disintegrating agents,for example, corn starch, or alginic acid; binding agents, for examplestarch, gelatin or acacia, and lubricating agents, for example magnesiumstearate, stearic acid or talc. The tablets may be uncoated or they maybe coated by known techniques to delay disintegration and absorption inthe gastrointestinal tract and thereby provide a sustained action over alonger period.

A tablet containing the composition of this invention may be prepared bycompression or molding, optionally with one or more accessoryingredients or adjuvants. Compressed tablets may be prepared bycompressing, in a suitable machine, the active ingredient in afree-flowing form such as powder or granules, optionally mixed with abinder, lubricant, inert diluent, surface active or dispersing agent.Molded tablets may be made by molding in a suitable machine, a mixtureof the powdered compound moistened with an inert liquid diluent. Eachtablet preferably contains from about 0.1 mg to about 500 mg of theactive ingredient and each cachet or capsule preferably containing fromabout 0.1 mg to about 500 mg of the active ingredient.

Compositions for oral use may also be presented as hard gelatin capsuleswherein the active ingredient is mixed with an inert solid diluent, forexample, calcium carbonate, calcium phosphate or kaolin, or as softgelatin capsules wherein the active ingredient is mixed with water or anoil medium, for example peanut oil, liquid paraffin, or olive oil.

Other pharmaceutical compositions include aqueous suspensions, whichcontain the active materials in admixture with excipients suitable forthe manufacture of aqueous suspensions. In addition, oily suspensionsmay be formulated by suspending the active ingredient in a vegetableoil, for example arachis oil, olive oil, sesame oil or coconut oil, orin a mineral oil such as liquid paraffin. Oily suspensions may alsocontain various excipients. The pharmaceutical compositions of theinvention may also be in the form of oil-in-water emulsions, which mayalso contain excipients such as sweetening and flavoring agents.

The pharmaceutical compositions may be in the form of a sterileinjectable aqueous or oleaginous suspension, or in the form of sterilepowders for the extemporaneous preparation of such sterile injectablesolutions or dispersions. In all cases, the final injectable form mustbe sterile and must be effectively fluid for easy syringability. Thepharmaceutical compositions must be stable under the conditions ofmanufacture and storage; thus, preferably should be preserved againstthe contaminating action of microorganisms such as bacteria and fungi.

Pharmaceutical compositions of the present invention can be in a formsuitable for topical use such as, for example, an aerosol, cream,ointment, lotion, dusting powder, or the like. Further, the compositionscan be in a form suitable for use in transdermal devices. Theseformulations may be prepared via conventional processing methods. As anexample, a cream or ointment is prepared by mixing hydrophilic materialand water, together with about 5 wt % to about 10 wt % of the compound,to produce a cream or ointment having a desired consistency.

Pharmaceutical compositions of this invention can also be in a formsuitable for rectal administration wherein the carrier is a solid. It ispreferable that the mixture forms unit dose suppositories. Suitablecarriers include cocoa butter and other materials commonly used in theart.

By “pharmaceutically acceptable” it is meant the carrier, diluent orexcipient must be compatible with the other ingredients of theformulation and not deleterious to the recipient thereof.

The terms “administration of” or “administering a” compound should beunderstood to mean providing a compound of the invention to theindividual in need of treatment in a form that can be introduced intothat individual's body in a therapeutically useful form andtherapeutically useful amount, including, but not limited to: oraldosage forms, such as tablets, capsules, syrups, suspensions, and thelike; injectable dosage forms, such as IV, IM, or IP, and the like;transdermal dosage forms, including creams, jellies, powders, orpatches; buccal dosage forms; inhalation powders, sprays, suspensions,and the like; and rectal suppositories.

The terms “effective amount” or “therapeutically effective amount” meansthe amount of the subject compound that will elicit the biological ormedical response of a tissue, system, animal or human that is beingsought by the researcher, veterinarian, medical doctor or otherclinician.

As used herein, the term “treatment” or “treating” means anyadministration of a compound of the present invention and includes (1)inhibiting the disease in an animal that is experiencing or displayingthe pathology or symptomatology of the diseased (i.e., arresting furtherdevelopment of the pathology and/or symptomatology), or (2) amelioratingthe disease in an animal that is experiencing or displaying thepathology or symptomatology of the diseased (i.e., reversing thepathology and/or symptomatology).

The compositions containing compounds of the present invention mayconveniently be presented in unit dosage form and may be prepared by anyof the methods well known in the art of pharmacy. The term “unit dosageform” is taken to mean a single dose wherein all active and inactiveingredients are combined in a suitable system, such that the patient orperson administering the drug to the patient can open a single containeror package with the entire dose contained therein, and does not have tomix any components together from two or more containers or packages.Typical examples of unit dosage forms are tablets or capsules for oraladministration, single dose vials for injection, or suppositories forrectal administration. This list of unit dosage forms is not intended tobe limiting in any way, but merely to represent typical examples of unitdosage forms.

The compositions containing compounds of the present invention mayconveniently be presented as a kit, whereby two or more components,which may be active or inactive ingredients, carriers, diluents, and thelike, are provided with instructions for preparation of the actualdosage form by the patient or person administering the drug to thepatient. Such kits may be provided with all necessary materials andingredients contained therein, or they may contain instructions forusing or making materials or components that must be obtainedindependently by the patient or person administering the drug to thepatient.

When treating or ameliorating a disorder or disease for which compoundsof the present invention are indicated, generally satisfactory resultsare obtained when the compounds of the present invention areadministered at a daily dosage of from about 0.1 mg to about 100 mg perkg of animal body weight, preferably given as a single daily dose or individed doses two to six times a day, or in sustained release form. Thetotal daily dosage is from about 1.0 mg to about 2000 mg, preferablyfrom about 0.1 mg to about 20 mg per kg of body weight. In the case of a70 kg adult human, the total daily dose will generally be from about 7mg to about 1,400 mg. This dosage regimen may be adjusted to provide theoptimal therapeutic response. The compounds may be administered on aregimen of 1 to 4 times per day, preferably once or twice per day.

The amount of active ingredient that may be combined with the carriermaterials to produce a single dosage form will vary depending upon thehost treated and the particular mode of administration. For example, aformulation intended for the oral administration to humans mayconveniently contain from about 0.005 mg to about 2.5 g of active agent,compounded with an appropriate and convenient amount of carriermaterial. Unit dosage forms will generally contain between from about0.005 mg to about 1000 mg of the active ingredient, typically 0.005,0.01 mg, 0.05 mg, 0.25 mg, 1 mg, 5 mg, 25 mg, 50 mg, 100 mg, 200 mg, 300mg, 400 mg, 500 mg, 600 mg, 800 mg or 1000 mg, administered once, twiceor three times a day.

It will be understood, however, that the specific dose level andfrequency of dosage for any particular patient may be varied and willdepend upon a variety of factors including the activity of the specificcompound employed, the metabolic stability and length of action of thatcompound, the age, body weight, general health, sex, diet, mode and timeof administration, rate of excretion, drug combination, the severity ofthe particular condition, and the host undergoing therapy.

Several methods for preparing the compounds of this invention areillustrated in the schemes and examples herein. Starting materials aremade according to procedures known in the art or as illustrated herein.The following examples are provided so that the invention might be morefully understood and are not to be construed as limiting the scope ofthe invention in any manner.

The following abbreviations may be used throughout the text:

Me: methyl

Et: ethyl

Bu: butyl

t-Bu: text-butyl

Ar: aryl

Ph: phenyl

Bn: benzyl

DMF: dimethylformamide

THF tetrahydrofuran

Ac: acetyl

DMSO: dimethylsulfoxide

DMEM: Dulbecco's Modified Eagle Medium (High Glucose)

FBS: fetal bovine serum

rt: room temperature

aq: aqueous

HPLC: high performance liquid chromatography

MS: mass spectrometry

equiv. equivalent

g gram

The following examples are provided to illustrate the invention and arenot to be construed as limiting the scope of the invention in anymanner.

A substituted hydrazine (1) can be combined with ethyl3-amino-3-ethoxyacrylate hydrochloride (2) in a solvent such as ethanolat elevated temperature to afford ethoxypyrazolone 3, which can betreated with an electrophile like N,N-dimethylformamide dimethylacetal(DMFDMA) to afford enamine 4. Generation of the anion of a substitutedpyridine like 5 with a base, such as sodium hydride, in a solvent liketetrahydrofuran can, when combined with 4, provide the alkylationproduct 6. Cyclization to the quinolizine 7 can be affected by heating 6in a solvent like diphenylether at elevated temperature. Partialreduction of the nitrile can be accomplished with a catalyst, likeplatinum(II) oxide in a solvent like formic acid to afford the aldehyde8, which can undergo reductive amination with amines in the presence ofacetic acid and a reducing agent such as sodium triacetoxyborohyride toafford compounds like 9.

Example 11-{[2-(2-Fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizin-5-yl]methyl}-4-(4-methylpyridin-2-yl)piperidine-4-carbonitrile

Step 1: Preparation of 4-(4-methylpyridin-2-yl)piperidine-4-carbonitrile

tert-Butyl 4-cyanopiperidine-1-carboxylate (0.220 g, 1.05 mmol) and2-fluoro-4-methylpyridine (0.107 g, 1.10 mmol, 1.05 equiv) weresuspended in THF (5 mL), cooled to 78° C., and treated with sodiumbis(trimethylsilyl)amide (1 M solution in diethyl ether, 1.47 mL, 1.47mmol, 1.40 equiv) dropwise. After 1 hour, the mixture was warmed toambient temperature, treated with saturated aqueous ammonium chloride,and extracted with dichloromethane (3×). The combined organic extractswere dried with sodium sulfate, filtered, and concentrated in vacuo. Theresidue was purified by silica gel chromatography (100:0 to 4:1hexanes:ethyl acetate), providing Cert-butyl4-cyano-4-pyridin-2-ylpiperidine-1-carboxylate. The resulting clear oilwas suspended in ethyl acetate (5 mL), cooled to 0° C. and saturatedwith gaseous hydrogen chloride. The mixture was warmed to ambienttemperature and after 18 hours, was concentrated in vacuo, providing thetitled compound.

Step 2: Preparation of5-ethoxy-2-(2-fluorophenyl)-2,4-dihydro-3H-pyrazol-3-one

(2-Fluorophenyl)hydrazine hydrochloride (1.00 g, 6.15 mmol) wassuspended in ethanol (10 mL), treated with ethyl3-amino-3-ethoxyacrylate hydrochloride (1.20 g, 6.15 mmol, 1.00 equiv),and placed into a preheated oil bath at 70° C. for 5 hours. The mixturewas cooled to ambient temperature, poured into saturated aqueous sodiumbicarbonate (100 mL), and extracted with ethyl acetate (3×75 mL). Thecombined organic extracts were dried with sodium sulfate, filtered, andconcentrated in vacuo. The residue was purified by silica gelchromatography (100:0 to 0:100 hexanes:ethyl acetate), providing thetitled compound.

Step 3: Preparation of(4E/Z)-4-[(dimethylamino)methylene]-5-ethoxy-2-(2-fluorophenyl)-2,4-dihydro-3H-pyrazol-3-one

5-Ethoxy-2-(2-fluorophenyl)-2,4-dihydro-3H-pyrazol-3-one (0.285 g, 1.28mmol) was suspended in N,N-dimethylformamide dimethylacetal (0.22 mL,1.67 mmol, 1.30 equiv) and placed into a preheated oil bath at 65° C.for 30 min. The mixture was cooled to ambient temperature andconcentrated in vacuo, providing the titled compound.

Step 4: Preparation of(3E/Z)-3-[3-ethoxy-1-(2-fluorophenyl)-5-oxo-1,5-dihydro-4H-pyrazol-4-ylidene]-2-pyridin-2-ylpropanenitrile

Pyridine-2-ylacetonitrile (0.137 g, 1.16 mmol, 1.25 equiv) was suspendedin THF (5 mL), cooled to 0° C., and treated with sodium hydride (0.045g, 1.1 mmol, 1.2 equiv). After 30 minutes, a suspension of(4E/Z)-4-[(dimethylamino)methylene]-5-ethoxy-2-(2-fluorophenyl)-2,4-dihydro-3H-pyrazol-3-one(0.258 g, 0.930 mmol) in THF (5 mL) was added and the mixture wasstirred at 0° C. for 45 minutes. The mixture was poured into sodiumbicarbonate (100 mL, saturated aqueous) and extracted with ethyl acetate(2×) and chloroform (4×). The combined organic extracts were dried withsodium sulfate, filtered, and concentrated in vacua. The residue waspurified by silica gel chromatography (100:0 to 0:100 hexanes:ethylacetate), providing the titled compound.

Step 5: Preparation of2-(2-fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizine-5-carbonitrile

(3E/Z)-3-[3-Ethoxy-1-(2-fluorophenyl)-5-oxo-1,5-dihydro-4H-pyrazol-4-ylidene]-2-pyridin-2-ylpropanenitrile(0.150 g, 0.428 mmol) was suspended in warm diphenylether (5 mL) andplaced into an oil bath preheated at 240° C. After stirring for 4 hours,the mixture was cooled to ambient temperature, diluted with hexanes (100mL), and filtered. The filtrate was further diluted with additionalhexanes (100 mL) and filtered. The collected solids were dissolved inchloroform, dried with sodium sulfated and and concentrated in vacua.The residue was purified by silica gel chromatography (100:0 to 0:100hexanes:ethyl acetate), providing the titled compound.

Step 6: Preparation of2-(2-fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizine-5-carbaldehyde

2-(2-Fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-e]quinolizine-5-carbonitrile(0.133 g, 0.437 mmol) was suspended in formic acid (90% aqueous, 5 mL),treated with platinum oxide (0.099 g, 0.44 mmol, 1.0 equiv) and placedinto an oil bath preheated to 60° C. for 2.5 hours. The mixture wascooled to ambient temperature and filtered through a pad of Celite. Thefiltrate was concentrated in vacua and the residue was purified bysilica gel chromatography (100:0 to 0:100 hexanes:ethyl acetate),providing the titled compound.

Step 7: Preparation of1-{[2-(2-fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizin-5-yl]methyl}-4-pyridin-2-yl)piperidine-4-carbonitrile

2-(2-Fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizine-5-carbaldehyde(0.025 g, 0.081 mmol) was suspended in a mixture of 1,2-dichloroethane(2 mL) and acetonitrile (4 mL) containing powdered 4 Å molecular sievesand treated with 4-(4-methylpyridin-2-yl)piperidine-4-carbonitrile(0.018 g, 0.094 mmol. 1.2 equiv), acetic acid (0.028 mL, 0.49 mmol, 6.0equiv), and sodium triacetoxyborohydride (0.034 g, 0.16 mmol, 2.0equiv). After stirring at ambient temperature for 60 hours, the mixturewas poured into saturated aqueous sodium bicarbonate and extracted withdichloromethane (2×).

The combined organic extracts were dried with sodium sulfate, filtered,and concentrated in vacuo. The residue was purified by silica gelchromatography (100:0 to 90:10 dichloromethane: 1% methanolic ammoniumhydroxide), providing the titled compound: ¹H-NMR (400 MHz, CDCl₃) δ9.21 (1H, d, J=6.9 Hz), 8.60 (1H, d, J=5.0 Hz), 8.31 (1H, d, J=9.0 Hz),8.28 (1H, s), 7.85 (1H, ddd, J=9.0, 7.0, 1.4 Hz), 7.70-7.66 (1H, m),7.46-7.42 (2H, m), 7.37-7.32 (1H, m), 7.28-7.22 (2H, m), 7.06 (1H, d,J=5.0 Hz), 3.84 (2H, s), 3.05 (2H, d, J 12.0 Hz), 2.62 (2H, br t, J=11.9Hz), 2.39 (3H, s), 2.31 (2H, td, J 13.2, 3.2 Hz), 2.06 (2H, br d J=13.4Hz) ppm; high resolution mass spectrometry (ES+) m/z 479.1982 [(M+H)⁺;calculated for C₂₅H₂₄FN₆O: 479.1990].

Example 22-(2-Fluorophenyl)-5-{[4-(1-methyl-1H-pyrazol-4-yl)-3-oxopiperazin-1-yl]methyl}pyrazolo[4,3-c]quinolizin-3(2H)-one

Step 1: Preparation of tert-butyl4-(1-methyl-1H-pyrazol-4-yl)-3-oxopiperazine-1-carboxylate

tert-Butyl 3-oxopiperazine-1-carboxylate (0.164 g, 0.819 mmol) wassuspended in isopropanol (3 mL) under an atmosphere of nitrogen andtreated with 1-methyl-4-iodo-1H-pyrazole (0.204 g, 0.983 mmol, 1.20equiv), ethylene glycol (0.051 g, 0.82 mmol, 1.0 equiv), copper iodide(0.031 g, 0.16 mmol, 0.20 equiv), and potassium phosphate (0.695 g, 3.28mmol, 4.00 equiv), and placed into a preheated oil bath at 100° C. for 8hours. The mixture was cooled to ambient temperature, concentrated invacuo and the residue was dissolved in dichloromethane, washed withwater, dried with sodium sulfate, filtered, and concentrated in vacuo.The residue was purified by silica gel chromatography (100:0 to 0:100hexanes:ethyl acetate), providing the titled compound.

Step 2: Preparation of 1-(1-methyl-1H-pyrazol-4-yl)piperazin-2-one

tert-Butyl 4-(1-methyl-1H-pyrazol-4-yl)-3-oxopiperazine-1-carboxylate(0.058 g, 0.21 mmol) was suspended in ethyl acetate (2 mL), cooled to 0°C., and saturated with gaseous hydrogen chloride. The mixture was warmedto ambient temperature and after 18 hours, concentrated in vacuo. Themixture was treated with sodium bicarbonate (aqueous saturated), washedwith a 10% solution of methanol in dichloromethane (3×), filtered, andconcentrated in vacuo, providing the titled.

Step 3: Preparation of2-(2-fluorophenyl)-5-{[4-(1-methyl-1H-pyrazol-4-yl)-3-oxopiperazin-1-yl]methyl}pyrazolo[4,3-c]quinolizin-3(2H)-one

Using the procedures described in Example 1, substituting1-(1-methyl-1H-pyrazol-4-yl)piperazin-2-one for4-(4-methylpyridin-2-yl)piperidine-4-carbonitrile (Step 7), the titledcompound was obtained: ¹H-NMR (400 MHz, CDCl₃) δ 9.23 (1H, d, J=7.0 Hz),8.27 (1H, d, J=9.2 Hz), 8.25 (1H, s), 8.02 (1H, s), 7.78 (1H, ddd,J=9.1, 6.9, 1.5 Hz), 7.69-7.65 (1H, m), 7.47 (1H, td, J=7.0, 1.3 Hz),7.44 (1H, s), 7.39-7.33 (1H, m), 7.29-7.23 (2H, m), 3.88 (3H, s), 3.84(2H, s), 3.62 (2H, t, J=5.5 Hz), 3.43 (2H, s), 2.84 (2H, t, J=5.6 Hz)ppm; high resolution mass spectrometry (ES+) m/z 472.1910 [(M+H)⁺;calculated for C₂₅H₂₃FN₇O₂: 472.1892].

The following compounds were prepared according to the general proceduredescribed in Examples 2, substituting the appropriate amine for1-(1-methyl-1H-pyrazol-4-yl)piperazin-2-one. The starting materials areeither commercially available, known in the literature or may beprepared from commercially available reagents using conventionalreactions well known in the art.

Ex. R Name HRMS/LRMS 3

2-(2-fluorophenyl)-5-{[1-(pyridin- 4-yl)-3,4-dihydroisoquinolin-2(1H)-yl]methyl}pyrazolo[4,3- c]quinolizin-3(2 H)-one C₃₁H₂₅FN₅O [M + H]calc. 502.2038 obs. 502.2040 4

1-{[2-(2-fluorophenyl)-3-oxo-2,3- dihydropyrazolo[4,3-c]quinolizin-5-yl]methyl}-4-(4- methoxypyridin-2-yl)piperidine-4-carbonitrile C₂₉H₂₆FN₆O₂ [M + H] calc. 509.2096 obs. 509.2094 5

2-(2-fluorophenyl)-5-({4-[4- (trifluoromethyl)phenyl]piperidin-1-yl}methyl)pyrazolo[4,3- yl)pyrazolo[4,3-c]quinolizin- 3(2H)-oneC₂₉H₂₅F₄N₄O [M + H] calc. 521.1659 obs. 521.1961 6

1-{[2-(2-fluorophenyl)-3-oxo-2,3- dihydropyrazolo[4,3-c]quinolizin-5-yl]methyl}-4- phenylpiperidine-4-carbonitrile C₂₉H₂₅FN₅O[M + H] calc. 478.2038 obs. 478.2053 7

4-(4-{[2-(2-fluorophenyl)-3-oxo- 2,3-dihydropyrazolo[4,3-c]quinolizin-5- yl]methyl}piperazin-1- yl)benzonitrile C₂₈H₂₄FN₆O [M +H] calc. 479.1990 obs. 479.2010 8

2-(2-fluorophenyl)-5-{[4-(1- methyl-1H-pyrazol-4- yl)piperazin-1-yl]methyl}pyrazolo[4,3- c]quinolizin-3(2 H)-one C₂₅H₂₅FN₇O [M + H] calc.458.2099 obs. 458.2091 9

5-[(4,4-difluoropiperidin-1- yl)methyl]-2-(2- fluorophenyl)pyrazolo[4,3-c]quinolizin-3(2 H)-one C₂₂H₂₀F₃N₄O [M + H] calc. 413.1584 obs. 413.158210

4-fluoro-1-{[2-(2-fluorophenyl)- 3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizin-5- yl]methyl}piperidine-4- carbonitrile C₂₃H₂₀F₂N₅O [M + H]calc. 420.1630 obs. 420.1627Biological Utility

The utility of the compounds as M1 receptor positive allostericmodulators may be demonstrated by methodology known in the art,including by the assay described below. The assay is designed to selectcompounds that possess modulator activity at the acetylcholinemuscarinic M1 receptor or other muscarinic receptors expressed inCHOnfat cells by measuring the intracellular calcium with a FLIPR³⁸⁴Fluorometric Imaging Plate Reader System. The assay studies the effectof one or several concentrations of test compounds on basal oracetylcholine-stimulated Ca²⁺ levels using FLIPR.

Compounds are prepared and subjected to a preincubation period of 4 min.Thereafter, a single EC₂₀ concentration of acetylcholine is added toeach well (3 nM final). The intracellular Ca²⁺ level of each sample ismeasured and compared to an acetylcholine control to determine anymodulatory activity.

Cells: CHOnfat/hM1, hM2, hM3 or hM4 cells are plated 24 hr before theassay at a density of 18,000 cells/well (100 μL) in a 384 well plate.CHOnfat/hM1 and CHOnfat/hM3 Growth Medium: 90% DMEM (Hi Glucose); 10% HIFBS; 2 mM L-glutamine; 0.1 mM NEAA; Pen-Strep; and Img/m1 Geneticin, areadded. For M2Gqi5CHOnfat and M4Gqi5CHOnfat cells, an additional 600ug/ml hygromycin is added.

Equipment: 384 well plate, 120 μL addition plate; 96-well Whatman 2 mlUniplate Incubator, 37° C., 5% CO₂; Skatron EMBLA-384 Plate Washer;Multimek Pipetting System; Genesis Freedom 200 System; Mosquito System;Temo Nanolitre Pipetting System; and FLIPR³⁸⁴ Fluorometric Imaging PlateReader System are used.

Buffers. Assay Buffer: Hanks Balanced Salt Solution, with 20 mM Hepes,2.5 mM Probenecid (Sigma P-8761) first dissolved in 1 N NaOH, 1% BovineSerum Albumin (Sigma A-9647). Dye Loading Buffer: Assay Buffer plus 1%Fetal Bovine Serum and Fluo-4AM/Pluronic Acid Mixture. 2 mM Fluo-4AMester stock in DMSO (Molecular Probes F-14202) Concentration of 2 μM inbuffer for a final concentration of 1 μM in Assay. 20% Pluronic AcidSolution stock, with concentration of 0.04% in Buffer, 0.02% in Assay.

65 μL of 2 mM Fluo-4AM are mixed with 130 μL of 20% Pluronic Acid. Theresulting solution and 650 μL FBS is added to the assay buffer for atotal volume of 65 mL. Positive Controls: 4-Br-A23187: 10 mM in DMSO;final concentration 10 μM. Acetylcholine: 10 mM in water, working stockat both 20 μM and 30 μM in assay buffer, final concentration of 10 μM.This is used to check the maximum stimulation of the CHOK1/hM1 cells. 20μM (2×) acetylcholine is added in the preincubation part of the assay,and the 30 μM (3×) stock is added in the second part.(EC₂₀)Acetylcholine: 10 mM in water, working stock of 9 nM (3×), andfinal concentration in assay is 3 nM. This is used after thepreincubation with test compounds. Addition of the EC₂₀ Acetylcholine toeach well with a test compound will ascertain any modulator activity. 24wells contain 3 nM Acetylcholine alone as a control.

Determining Activity of Putative Compounds:

Screening Plate: Compounds are titrated in 96-well plates (columns2-11), 100% DMSO, started at a concentration of 15 mM (150× stockconcentration), and 3-fold serial dilutions using Genesis Freedom200System. Four 96-well plates are combined into a 384-well plate usingMosquito Nanolitre Pipetting System by transferring 1 μl of serialdiluted compounds to each well, and 1 mM acetylcholine (100× stockconcentration) were added as a control. Using Temo, 49 μl assay bufferis added to each well of the 384-well plate right before assay.

In a 96-well Whatman 2 ml Uniplate, 9 nM Acetylcholine (3×) is pipettedinto wells corresponding to the screening compounds, and into controlwells. The 30 μM acetylcholine control (3×) is added into control wells,and the 3× agonist plate is transferred into a 384 well plate.

Cells are washed three times with 100 μL of buffer, leaving 30 μL ofbuffer in each well. Using Multimek, 30 μL of Dye Loading Buffer isadded into each well and incubated at 37° C., 5% CO₂ for up to one hr.

After 60 min, the cells are washed three times with 100 μL of buffer,leaving 30 μL of buffer in each well. The cell plate, screening plate,and agonist addition plates are placed on the platform in the FLIPR andthe door closed. A signal test to check background fluorescence andbasal fluorescence signal is performed. Laser intensity is adjusted ifnecessary.

4 min of preincubation with the test compounds is provided to determineany agonist activity on the M1 receptor by comparison to the 1 mMacetylcholine control. After preincubation, the EC₂₀ value ofacetylcholine (3 nM final) is added to determine any modulator activity.

A further description of the muscarinic FLIPR assay can be found inInternational patent application WO2004/073639.

In particular, the compounds of the following examples had activity inthe aforementioned assay, generally with an IP (inflection point) of 10μM (10,000 nM) or less. The inflection point is calculated from theFLIPR values, and is a measure of activity. Such a result is indicativeof the intrinsic activity of the compounds in use as M1 allostericmodulators.

IP values from the aforementioned assay for representative exemplarycompounds of the invention (as described herein) are provided below inTable 1 below:

M1 IP Value Example (nM) 1 175 2 322

While the invention has been described and illustrated with reference tocertain particular embodiments thereof, those skilled in the art willappreciate that various adaptations, changes, modifications,substitutions, deletions, or additions of procedures and protocols maybe made without departing from the spirit and scope of the invention. Itis intended, therefore, that the invention be defined by the scope ofthe claims that follow and that such claims be interpreted as broadly asis reasonable.

What is claimed is:
 1. A compound of formula (I):

and pharmaceutically acceptable salts thereof, wherein R¹ represents—NR²R³, or a nitrogen containing C₅₋₁₀ heterocyclyl; wherein saidheterocyclyl is optionally substituted with one or more of R^(a); R² andR³ independently represent (a) hydroxy, (b) —O—C₁₋₆ alkyl, said alkyloptionally substituted with 1 to 3 groups of R^(a); (c) —C₁₋₆ alkyl,said alkyl optionally substituted with 1 to 3 groups of R^(a); (d)-hydrogen; R^(a) represents: (a) halogen, (b) hydroxy, (c) —O—C₁₋₆alkyl, said alkyl optionally substituted with 1 to 3 groups of halo; (d)—C₁₋₆ alkyl, said alkyl optionally substituted with 1 to 3 groups ofhalo; (e) cyano, (f) —NR^(A)R^(B), wherein R^(A) and R^(B) are selectedfrom the group consisting of (i) hydrogen, (ii) —C₁₋₆ alkyl, or R^(A)and R^(B) are linked together with the nitrogen to which they are bothattached to form a 2-6 membered carbocyclic ring, wherein one or two ofthe ring carbon atoms is replaced by a nitrogen, oxygen or sulfur, andthe carbocyclic is optionally substituted with one or more C₁₋₆ alkyl,(g) represents —C(═O)—R^(C), —S(O)_(n)—R^(C); C₅₋₁₀ heterocyclyl, andC₆₋₁₀ aryl, said heterocyclyl and aryl optionally substituted with 1 to3 groups of R^(C); and wherein R^(C) is selected from the groupconsisting of (i) hydrogen, (ii) —C₁₋₆ alkyl, (iii) —O—C₁₋₆ alkyl, (iv)CF₃, (v) halogen, (vi) cyano, n is 0, 1 or
 2. 2. The compound accordingto claim 1 wherein R¹ is —NR²R³.
 3. The compound according to claim 1wherein R¹ is a nitrogen containing C₅₋₁₀ heterocyclyl; wherein saidheterocyclyl is optionally substituted with one or more of R^(a).
 4. Thecompound according to claim 3 wherein R¹ is selected from the groupconsisting of optionally substituted piperazinyl, piperidinyl, azepinyl,tetrahydroisoquinolinyl, tetrahydroquinolinyl, pyrrolidinyl,oxopiperazinyl, oxopiperidinyl, and oxopyrrolidinyl.
 5. The compoundaccording to claim 3 wherein R¹ is optionally substitutedoxopiperazinyl, piperazinyl, and piperidinyl.
 6. The compound accordingto claim 1 wherein R^(a) is selected from the group consisting of cyano,halogen, —C₁₋₆ alkyl, —O—C₁₋₆ alkyl, CF₃, C₅₋₁₀ heterocyclyl, C₆₋₁₀aryl, said heterocyclyl, aryl optionally substituted with 1 to 3 groupsof R^(C).
 7. The compound according to formula (I) of claim 1represented by formula (II):

or a pharmaceutically acceptable salt thereof wherein R^(a) is selectedfrom the group consisting of cyano, halogen, —C₁₋₆ alkyl, —O—C₁₋₆ alkyl,CF₃, C₅₋₁₀ heterocyclyl, C₆₋₁₀ aryl, said heterocyclyl, aryl optionallysubstituted with 1 to 3 groups of R^(C).
 8. The compound according toclaim 7 wherein R^(a) is selected from the group consisting of cyano,fluoro, chloro, bromo, iodo, methoxy, CF₃, methyl, ethyl, propyl, butyland optionally substituted phenyl, pyridyl, pyrazolyl, and imidazolyl.9. The compound according to formula (I) of claim 1 represented byformula (III):

or a pharmaceutically acceptable salt thereof, wherein R^(a) is selectedfrom the group consisting of cyano, halogen, —C₁₋₆ alkyl, —O—C₁₋₆ alkyl,CF₃, C₅₋₁₀ heterocyclyl, C₆₋₁₀ aryl, said heterocyclyl, aryl optionallysubstituted with 1 to 3 groups of R^(C) and A is C₅₋₁₀ heterocyclyl, orC₆₋₁₀ aryl, said heterocyclyl, aryl optionally substituted with 1 to 2groups of R^(a).
 10. The compound according to claim 9 wherein R^(a) isselected from the group consisting of cyano, fluoro, chloro, bromo,iodo, methoxy, CF₃, methyl, ethyl, propyl, butyl and optionallysubstituted phenyl, pyridyl, pyrazolyl, and imidazolyl.
 11. A compoundwhich is:1-{[2-(2-fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizin-5-yl]methyl}-4-(4-methylpyridin-2-yl)piperidine-4-carbonitrile;2-(2-fluorophenyl)-5-{[4-(1-methyl-1H-pyrazol-4-yl)-3-oxopiperazin-1-yl]methyl}pyrazolo[4,3-c]quinolizin-3(2H)-one;2-(2-fluorophenyl)-5-{[1-(pyridin-4-yl)-3,4-dihydroisoquinolin-2(1H)-yl]methyl}pyrazolo[4,3-c]quinolizin-3(2H)-one,1-{[2-(2-fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizin-5-yl]methyl}-4-(4-methoxypyridin-2-yl)piperidine-4-carbonitrile,2-(2-fluorophenyl)-5-({4-[4-(trifluoromethyl)phenyl]piperidin-1-yl]methyl)pyrazolo[4,3-yl)pyrazolo[4,3-c]quinolizin-3(2H)-one,1-{[2-(2-fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizin-5-yl]methyl}-4-phenylpiperidine-4-carbonitrile,4-(4-{[2-(2-fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizin-5-yl]methyl}piperazin-1-yl)benzonitrile,2-(2-fluorophenyl)-5-{[4-(1-methyl-1H-pyrazol-4-yl)piperazin-1-yl]methyl}pyrazolo[4,3-c]quinolizin-3(2H)-one,5-[(4,4-difluoropiperidin-1-yl)methyl]-2-(2-fluorophenyl)pyrazolo[4,3-c]quinolizin-3(2H)-one,4-fluoro-1-{[2-(2-fluorophenyl)-3-oxo-2,3-dihydropyrazolo[4,3-c]quinolizin-5-yl]methyl}piperidine-4-carbonitrile,and pharmaceutically acceptable salts thereof.
 12. A pharmaceuticalcomposition comprising a therapeutically effective amount of a compoundof claim 1, or a pharmaceutically acceptable salt thereof, and apharmaceutically acceptable carrier.
 13. A pharmaceutical compositionfor the treatment of a disease or disorder mediated by the muscarinic M1receptor, wherein said disease or disorder is selected from the groupconsisting of Alzheimer's disease, schizophrenia, pain or sleepdisorders, comprising a therapeutically effective amount of a compoundof claim 1, or a pharmaceutically acceptable salt thereof, and apharmaceutically acceptable carrier.
 14. A method of treating a diseaseor disorder mediated by the muscarinic M1 receptor, wherein said diseaseor disorder is selected from the group consisting of Alzheimer'sdisease, schizophrenia, pain or sleep disorders in a patient in needthereof, comprising administering to the patient a therapeuticallyeffective amount of a compound of claim 1, or a pharmaceuticallyacceptable salt thereof, and a pharmaceutically acceptable carrier.